Ignition apparatus



19345 H. L. HARTZELL. 1,981,041

IGNITION APPARATUS Filed Jan. 2. 1932 Patented 11011.20. 1934 PATENT OFFICE rom'rron arraaarus Herman L. Hartzell, Anderson, Ind., assignor, by

mesne assignments, to General Motors Corporation,'Detroit, Mich., a corporation of Delaware Application January 2, 1932, Serial No. 534,526

8 Claims.

' This invention relates to an ignition apparatus for an internal combustion engine and more particularly to the circuit interrupter of an ignition timer distributor unit comprising a circuit breaker lever operated upon by an engine breaker cam and carrying a contact engageable with a relatively stationary contact mounted upon a contact bracket adjustable with respect to the breaker lever for the purpose of adjusting the amount of lo separation produced by the cam. Heretofore it has been the practice to mount the contact breaker coaxially with the circuit breaker lever so that, regardless of adjustment of the contact bracket the relation between the contact carried by the lever and the contact carried by the bracket would remain the same. This known construction has been found to be advantageous when employing-contacts having plane contact engaging surfaces. Obviously, if the apparatus a is constructed properly so that the plane contact engaging surfaces will make good engagement with each other for an initialv adjustment of the stationary contact bracket, the contact engagement will be satisfactory for other positions of 5 the contact bracket.

It is one of the objects of the present invention to reduce the cost of manufacture of circuit interrupters of this type and this object is accomplished in the present invention by pivotally supporting the stationary contact bracket not upon s'an axis coaxial with the circuit breaker lever but 'upon an axis which will permit the contact bracket to be shortened so that less material will be employed. While such construction does not pro- '35 wide for maintaining the same relation between the contacts of the circuit interrupter for all adjustments of the stationary contact bracket, a satisfactory circuit interrupter can be provided. when at least one of the contacts is provided with a convex contact-engaging surface. The pivotal support of the stationary contact bracket is provided byextruding a cylindrical portion of material from the interrupter supporting plate. Thus the number of parts is not increased.

Further objects and advantages of the present invention will be apparent from the following description. reference being had to the accompanying drawing wherein a preferred embodi- V must of one form of the present invention is clearly shown.

In the drawing: a Hz. 1 is a plan view of an ignition timer having a angle circuit interrupter embodying the present invention.

Fig. 2 is a sectional view of the line 2-2 of Fig. 1.

Fig. 3 is a plan view of an ignition timer having two circuit interrupters embodying the present invention. 5

Figs. 4 and 5 are sectional views taken respectively on the lines 4-4 and 55 of Fig. 3.

Referring to Fig. 1 20 designates an ignition timer housing enclosing a circuit breaker plate 21 having ears 22 by which the plate is secured to the interior of the housing 20 by screws 23. The

housing encloses a, centrally disposed engine driven cam 24 which operates upon a circuit breaker rubbing block 25, which, together with one end of a leaf spring conductor 26, is fastened to a circuit breaker lever 27 carrying a contact 28 having a plane contact-engaging surface engageable with a contact 29 having a convexcontactengaging surface. Contact 29 is attached to an ear 30 provided by a contact bracket 31 pivotally mounted upon an extrusion or pivot 32 provided by the plate 21 as shown more clearly in Fig. 2. The lever 27 is generally channel-shaped in crosssection and is provided with two hub portions 27a into which a nonconducting bushing 34 is pressed to provide a nonconducting journal for the lever 2'1 upon a stud 35 having a flange 36 and riveted to the plate 21 by the shank portion 37. The flange 36 spaces the bushing 34 above the plate 21. The leaf spring conductor 26 is electrically connected with an insulated terminal 38 upon which is mounted a clip 39 connected with an ignition condenser not shown.

The bracket 31 can be secured in various positions ofadjustment relative to the pivot 32 by a screw 40 having threaded engagement with the plate 21 and passing through an arcuate slot provided in the bracket 31 concentric with the pivot 32. To adjust the plate 31 a screw driver is applied to the screw 40 to loosen the same and then this same screw driver may be applied to a screw driver slotted disc 42 having an eccentric shank 43 journalled in the plate 21. The head of the disc 43 is received by a slot 44 provided by the bracket 31 and the slot 44 extends substantially radially with respect to the pivot 32. After the proper adjustment has been made to give the desired amount of contact separation effected by cam 24 the screw driver is again applied to the screw 40 to tighten the same upon the plate 21.

It will be apparent that the adjusting of the plate 31 about the pivot 32 which is not in coaxial relation with the circuit breaker lever stud 35 will change somewhat the relation between the contacts 28 and 29, but this change in rela- 0 tionshipdoes not affect the operation of the timersince the contact 29 has a convex engaging surface which will make as good a contact with the plane surface of the contact 28 as is required for proper ignition regardless of the position of the bracket 31 within the limits of adjustment that are necessary.

Referring to Fig. 3, 5O designates an ignition timer housing enclosing two circuit interrupters mounted upon a circuit breaker plate-51 provided with ears 52 which are attached by screws 53 to the housing and rest upon a ledge 50a shown in Fig.

5. The plate 51 is provided with a central opening 54 providing a bearing for a journal-flange 55 integral with a circuit breaker adjusting plate 56 as described and claimed in the patentto John T; Fitzsimmons #1,825,720. The plate 56carries a stud 35 supporting a circuit breaker lever 27 in the manner shown in Fig. 1. The contact 28 of this lever 27 cooperates with a contact 29 attached to an ear 60 of a contact bracket 61 pivotally supported upon apivot 62 provided by the plate 56. The bracket 61 is secured in adjusted position by a screw 63 passing through. an arcuate slot 64 provided by the plate 61 and threadedly engaging the plate 56. When the screw 63 is loosened the bracket 61 may be adjusted about the pivot 62 by applying the screw driver to a screw driver slotted disc 65 having an eccentric shank 66 pivoted in the plate 56' and having its head received by a slot 6'? provided by the bracket 61 and located substantially radially with respect to the pivot 62. The leaf spring conductor 26 controlling the upper circuit breaker lever 27 in Fig. 3 is attached by a screw 70 and a nut 70a. to a conducting strap 71 insulatingly supported by ears 72 and 73 integral with the plate 51. The strap '71 is attached as shown in Figs. 3 and 5 to an insulated terminal screw 74 passing through a nonconducting bushing 75 and carrying a strap 76 for making connection with an ignition condenser, not shown.

The plate 51 is provided also with a pivot 62a providing a pivot support for a second contact bracket 61a of the same construction as the upper bracket 61. Bracket 61a carries a contact 29 cooperating with a contact/28 of circuit breaker lever 27 insulatingly pivoted upon a stud 35 carried directly by the plate 51. The leaf spring conductor 26 of this last mentioned circuit breaker lever 27 is electrically connected and mechanically fastened to the strap '71.

The circuit breaker will be operated upon alternately by a cam 90. In order to synchronize the operation of the two circuit breakers, the plate 56 is adjustable first by loosening screws 80 and 81 which pass through arcuate slots 82 and 83 provided by plate 56 and then turning a screw driver slotteddisc 85 having an eccentric shank 86 pivotally carried bythe plate 51, the disc being received by a slot 87 provided by plate 61- and located substantially radially'with respect to the cam 90. After the proper adjustment has been made, the screws 80 and 81 are screwed into the tapped holes provided for them by the plate 51 in order that the heads of these screws will clamp the plate 56 to the plate 51.

It is therefore. apparent that less material is required formaking contact brackets 31, 61 and 61a than would be required if these brackets were pivoted upon' the adjacent circuit breaker supporting studs 35. This economy is not offset byadding parts to provide a separate pivotal support'for the contact bracket since metal has been extruded from the'circuit breaker plate to provide the necessary pivot. It is not necessary to add parts to retain the contact bracket upon its pivot since the screw which holds the contact bracket in the desired position of axial adjustment with respect to itspivot also serves to prevent lateral movement of the contact bracket with respect to the circuit breaker plate, thereby retaining the bracket upon its pivot.

While the form of embodiment of the present invention as herein disclosed. constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A circuit interrupter comprising, in combination, a stationary mounting plate, a post attached thereto, a circuit breaker lever pivoted upon said post, a rubbing block carried by the lever, a rotary cam. operating upon the rubbing block, a second pivot post provided integrally by the mounting plate and spaced substantially from the first post, a bracket pivoted upon the second post and supported by the mounting plate, cooperating interrupter contacts attached respectively to the lever and bracket, at least one of the contactshaving a convex surface engaged by the other contact, eccentric means for moving the bracket about its pivot to change the relation of the engaging surfaces of the contacts and simultaneously changing the point at which the rubbing block of the lever engages the cam to vary the distance of separation of the contacts and means for securing the bracket to the mounting plate in a desired position of angular adjustmentwith respect to its pivot.

2. A circuit interrupter comprising, in combinatioma fixed, mounting plate, a post attached thereto, a circuit breaker lever pivoted upon said post, a rubbing block carried by the lever, a rotary cam operating upon the rubbing block, a second post provided by the mounting plate and located near the first post and on the same side of the rubbing block with respect to, which the first post is located, a bracket pivoted upon the second post and supported by the mounting plate, cooperating interrupter contacts attached respectively to the lever and bracket, at least one of the contacts having a convex surface engaged by the other contact, means for moving the bracket about the second post to shift the engaging portions of the contacts and simultaneously changing the point at which the rubbing block engages the cam to vary the distance of separation between the contacts, and means for securing the bracket to the mounting plate in a desired position of angular adjustment with respect to its pivot. f

3. A circuit interrupter comprising, in combination, a fixed mounting plate, a post attached thereto, a circuit breaker lever pivoted upon 'said post, a rubbing block carried by the lever, a-rotary cam operating upon the rubbing block, a second post provided by the mounting plate and located near the first post and on the same side-of the rubbing block with respect to which the first lpost is located, a bracket pivoted upon the second-post and supported by the mounting plate, cooperating interrupter contacts attached respectivelyto the lever and bracket, at least one of the.acontacts having a convex surface engaged by the other contact, screw driver operated means for adjusting only the bracket and its contact angularly with respect to its pivot post torsim'ultaneously change the relation of the contacting surfaces oi the contacts and the distance of separation between the contacts, and screw driver operated means for securing the bracket to the mounting plate in a desired position of angular adjustment with respect to its pivot.

4. A circuit interrupter comprising, in combination, a stationary mounting plate, a post attached thereto; a circuit breaker lever pivoted upon said post a rubbing block carried by the lever, a rotary cam operating upon the rubbing block, a second pivot post provided integrally by the mounting plate and spaced substantially from the first post, a bracket pivoted upon the second .post and supported by the mounting plate, cooperating interrupter contacts attached respectively to the lever and bracket, at least one of the contacts having a convex surfaceengaged by the other contact, a rotatable adjusting member carried by the mounting plate and having an eccentric head extending into an aperture of the bracket for adjusting the pivoted plate relative to the mounting plate to adjust the rubbing block relative to the axis of the cam, and means for securing the bracket to the mounting plate in a desired position of angular adjustment with respect to its pivot.

5. An ignition distributor comprising in combination, a housing; a stationary mounting plate secured to said housing; a cam rotatable within the housing centrally thereof; a breaker lever pivotally supported on said plate and carrying a rubbing block and an interrupter contact; a bracket carrying a contact cooperating with the contact on said lever, at least one of the contacts having a convex surface, said bracket being pivotally supported by the plate independently with respect to the breaker lever; means for rotating said bracket about its pivot to adjust the rubbing block relative to the axis oi the cam "means for securing said bracket to the mounting plate in adjusted position.

6. In a device of the character described the combination comprising, a mounting plate, a post attached thereto, an arm pivoted upon said post, a second post provided by the plate, a bracket pivoted upon said second post, a contact point carried by the arm and the bracket to cooperate with each other, means operable upon said arm to open and close said contacts, and means for adjusting the bracket to change the point of engagement of said contacts.

7. In a device or the character described the combination comprising, a movable member carrying a contact and pivoted upon a post, a normally stationary member carrying a contact to cooperate with the first mentioned contact, one of said contacts having a convex surface, said stationary member pivoted upon a second post and spacedsubstantially from the first post, and means for moving said stationary member and its contact about their pivot so that the contacts will engage at a different point upon their contact surfaces.

8. In a device of the character described, the combination with a pair of contact members, means for moving one of said contact members toward and from the other member which is normally stationary, each 01 said membersprovided with a contact to engage the contact carried by the other member, at least one of said contacts having a convex surface, means for adjusting the stationary member so as to change the point of engagement on the surfaces oi said contacts.

HERMAN L. HARTLELL. 

